Plastics are bad. But are alternatives worse?

BIOPLASTICS have been hailed by some as a solution to the plastic problem [1,3]. They look and feel similar to conventional plastic, but are made from renewable resources, such as corn starch, instead of oil [3]. In theory they have two advantages: rapid breakdown, and a low carbon footprint [1,2]. Is this true?

Do they DEGRADE? Sometimes, and not that quickly. In theory, bioplastics should degrade into natural materials which do not pollute the environment [3]. However, they often last for years in soil or seawater [4,9,10], or leave toxic chemicals behind [3]. Some break down in industrial composting facilities, but not in garden compost heaps or landfill [3].

What about their CARBON FOOTPRINT? Bioplastics can have a lower carbon footprint than most plastic [8,16] because they are made from plants: the plants took in CO2 from the atmosphere through photosynthesis, which is then released again when the bioplastic breaks down [12,17]. While this is carbon neutral, there are some CO2 emissions production process to make bioplastics [12].

The plants grown to make bioplastic take up farmland that could be used to grow food [3]; this can result in deforestation to grow more crops [16,18], causing release of CO2 from forests [19]. One study showed that replacing all plastic with bioplastic would take up to 219 million hectares of land (61% of all free arable land) [16]. Luckily, not all bioplastic requires extra land, such as that made from farm waste [13,14].

Another alternative is BIODEGRADABLE plastics, which (like plastic) are made from oil [3]. They are very different from bioplastic, despite the similar name! They are not really any better than normal plastic [6,7]. They degrade faster, but not into natural materials, and produce just as much methane in landfills [3,15].

In the future we will likely have much more planet-friendly plastics [10,11,5]. However, for now, using the popular alternatives is no excuse for wastefulnes [20]. Perhaps the problem is not plastic, but our wasteful use and careless disposal of it.